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防皱纤维素纤维的制备与性能研究
【作者】 刘杰；
【导师】 朱平；
【作者基本信息】 青岛大学 ， 材料学， 2015， 博士
【摘要】 本文研究了从纺织的源头纤维的制备来解决再生纤维素织物易起皱问题的方法。研究内容主要分为两大部分,一是采用氯化锂/二甲基乙酰胺(Li Cl/DMAc)溶液为纤维素溶剂,在纺丝液中添加聚氨酯组分(氨纶级TPU),经湿法纺丝,制备再生纤维素/TPU复合纤维;二是采用离子液体为纤维素溶剂,在纺丝液中添加1,2,3,4-丁烷四羧酸(BTCA)和次亚磷酸钠(SHP),经湿法纺丝,制备BTCA交联再生纤维素纤维。研究内容主要有以下几个方面:(1)纤维素与TPU在Li Cl/DMAc中的相容性采用稀溶液粘度法,判断纤维素与TPU在溶剂体系中的相容性,研究发现μ与a均大于零,两类判据结论一致,表明两类聚合物相容性良好。(2)纤维素/TPU复合纺丝液的流变性能采用高级旋转流变仪MCR301测试了纤维素/TPU复合纺丝液的流变性能,分析结果表明,该体系呈现切力变稀现象,属于非牛顿流体,非牛顿指数随TPU质量分数的增大而增大;动态储能模量与损耗模量随剪切频率的增大而增大;粘流活化能随剪切速率的增大而减小,粘度对温度的变化敏感性随剪切频率的增大而减小。(3)再生纤维素/TPU复合纤维的制备及性能采用湿法制备了再生纤维素/TPU复合纤维,通过正交实验以纤维折痕回复性及纤维的拉伸强度为评价指标确定出纺丝原液的最佳配制条件,并优化凝固浴工艺,得到再生纤维素/TPU复合纤维的最佳制备工艺:纺丝液浓度6wt%,温度20℃,TPU:纤维素(质量比)为3:10,凝固浴温度20℃,凝固浴长度100cm,凝固浴中Li Cl浓度15wt%,牵伸倍率为200%,此工艺下制得的复合纤维折痕回复角提高了64.4%,断裂伸长率提高了59.9%,拉伸强度略有下降。(4)BTCA交联再生纤维素纤维的制备及性能测试了免烫整理剂BTCA与催化剂SHP在离子液体中的溶解性,研究了小分子添加剂对纤维素纺丝溶液流变性能的影响,通过单因素分析确定制备交联纤维的最佳工艺:BTCA质量分数4%(质量比BTCA:SHP=8:5),添加入纤维素纺丝液中共混均匀进行纺丝,经40℃的1%稀硫酸凝固浴,凝固30s,两段牵伸,每段牵伸倍率为1.5倍,90℃预烘2.5min,180℃焙烘3min,温水洗,烘干,得到交联纤维,其干湿折痕回复角分别提高了76.4%与41.1%。纤维交联前后XRD分析表明,交联反应发生在纤维素的可及区,交联前后纤维素的晶型未发生改变,均为纤维素II晶型,只是纤维素II晶胞参数稍有变化,结晶度稍有升高。
【Abstract】 In this study, the fibre modification process was carried out in advance at the spinning stage. In the first part, regenarated cellulose/TPU composite fibre was prepared in Li Cl/DMAc solvent, which is the key research content. In the second part, BTCA crosslinking cellulose fibre was prepared in ionic liquid solvent. The main contents are as follows:(1) The compatibility of cellulose and TPU in Li Cl/DMAc solvent was studied accordding to dilute-solution viscometry, based on μ and a criteria of classic Huggins equation. It was shown that the conclusion was consistent: μ and a value was greater than zero, indicating the compatibility of cellulose and TPU was excellent.(2) The rheological property of cellulose/TPU blend spinning solution was studied by an advanced rotary rheometer. The static rheological measurements results showed that the viscosity decreased with increasing shear rates, exhibiting shear thinning behavior. The viscosity also decreased with increasing temperatures.The dynamic rheological measurements showed that the storage modulus of G’ and the loss modulus G’’ both increase with increasing frequencies. The non-Newtonian index of blend solutions increased with increasing TPU content, while the flow activation energy decreased with increasing shear rate.(3) The cellulose/TPU composite fibre was prepared using wet spinning method. The optimum process of spinning conditions and coagulation conditions was obtained by orthogonal test. The optimum process was obtained as follows: spinning solution concentration 6wt%, spinning temperature 20 ℃, TPU to cellulose(mass ratio) 3:10, coagulation bath temperature 20℃, coagulation bath length 100 cm, Li Cl mass ratio 15w%, draft ratio 200%. Under the optimum pocess, the WRA of the composite fiber was improved by 64.4% and the elongation was improved by 59.9% while the tensile strength decreases a little. The preparation method of BTCA crosslinking fibre was investigated. The dissolving property of BTCA and SHP in ionic liquid was studied. The influence of small molecule additive on the rheological property of spinning solution was studied. The optimum preparation process was obtained by single factor analysis : 4wt% BTCA(BTCA:SHP=8:5) was added into cellulose spinning solutions and then solidified for 30 s in 1wt% dilute sulfuric acid solution, two draft, precured at 90℃ for 2.5min and cured at 180℃ for 3min. The cross-linked fibre was obtained after washed in warm water. The dry WRA and wet WRA was improved by 76.4% and 41.1%, respectively.